Figure below shows a hypothetical atom with a ground state of -10 eV that is radiated by

The image shows a Bohr model-like diagram of an atom. The ground state is at $-10$ eV. The edge of the atom (ionization level) is at $0$ eV. A photon of $12$ eV energy is shown incident on the electron in the ground state. The diagram labels the energy difference between the ground state and the edge of the atom as 'Work function, $\phi$' and the energy of the ejected electron above $0$ eV as 'Maximum kinetic energy, $K_{max}$'.